1. Field of Invention
The invention relates to a control device for a hybrid vehicle. More specifically, the invention relates to a control device for a hybrid vehicle that is able to inhibit generation of a jolt which is unpleasant for an occupant of the hybrid vehicle and which is caused by change of an application state of a take-off clutch within an automatic speed change mechanism when an accelerator pedal is depressed to make the hybrid vehicle start moving (take-off).
2. Description of Related Art
Conventionally, art has been proposed (for an example, see Japanese Patent Laid-Open Publication No. 07-293687) for a torque converter type automatic transmission that is mounted in a vehicle in which, when the vehicle is stopped with the shift range left in a drive range, a predetermined friction engagement element (clutch) within the transmission (automatic speed change mechanism) is caused to slip such that a neutral state is approached. This art executes a so-called neutral control in which, for example, a fluid pressure supplied to a hydraulic servo of a clutch assisting with the start of movement (hereinafter referred to as a “take-off clutch”) within the transmission is regulated based upon predetermined conditions such that the take-off clutch is able to maintain a slipping state. Further, it is possible to promote a smooth start-up of movement because, when the take-off clutch moves from the slipping state to a fully applied state, the fluid pressure of the hydraulic servo is determined based upon various conditions, such as a target application time and an input torque to the transmission.
Moreover, by executing the neutral control while the vehicle is stopped, torque transmitted to driven wheels via the torque converter and the transmission is reduced. Accordingly, an increase in fuel consumption resulting from drag of the torque converter while the vehicle is stopped by depression of a brake pedal is inhibited, and it is possible to reduce vibrations caused by idle revolution.